Automatic pressure-governor.



W. J; RICHARDS.

AUTOMATIO PRESSURE GOVERNOR. APPLICATION FILED JUNE 29, 1907.

Patented Feb. 14, 1911.

UNITED STATES PATENT OFFICE.

WALTER J. RroHARns, or MILWAUKEE, wIsCoNsIN, ASSIGNOR T NATIONAL BRAKE &ELECTRIC COMPANY, OF MILWAUKEE, WIsCoNsIN, A CORPORATION or wIsCoNsrN.

AUTOMATIC PRESSURE-GOVERNOR.

Specification of Letters Patent. Application filed June 29, 1907. SerialNo. 381,506.

Patented Feb. 14, 1911;

To all whom it may concern:

Be it known that I, WALTER J. RICHARDS, residing in Milwaukee, in thecounty of Milwaukee and State of Wisconsin, have invented new and usefulImprovements in Automatic Pressure-Governors, of which the t followingis a description, reference being. had to the accompanying drawings,which I are a part of this specification.

This invention has for its object to provide an automatic pressuregovernor particularly adapted for controlling the opera tion of a motorcompressor to maintain a given range of pressure in a fluid pressuresystem.

Another object of this invention is to dispense with the necessity forauxiliary or supplemental switches by providing a pressure controlledswitch capable of alone caring for the motor circuit.

Another object of this invention is to provide a pressure actuatedswitch with a means for producing a quick make and break, comprising amagnet attracting the switch arm for accelerating its closing move mentand for retarding its opening movement until the influence of the airpressure has reached such a degree as to overcome the tendency of themagnet and. produce a sudden opening movement of the switch.

WVith the above and other objects in view the invention consists in theautomatic pressure governor claimed, its parts and combinations of partsand all equivalents.

Referring to the accompanying drawings in which like characters ofreference indicate the same parts in the different views; Figure l is afront View of an automatic pressure governor constructed in accordancewith this invention, with the cover removed and with the insulating diskbroken away to disclose parts there behind, the governor being connectedwith a fluid pressure system and the motor compressor thereof shown indiagram; and, Fig. 2 is a central sectional plan View of said automaticpressure governor. p

In these drawings 6 represents a casing which is preferably of iron andof the cylindrical shape as shown, with a removable cover 7 of likematerial clamped thereto by means of swinging bolts 8. The casingcontains a Bourdon tube 9 having a suitable connection 10 for couplingit with the reservoir 11 of a fluid pressure system, usually] an airbrake system for electric railway cars. The closed movable end of theBourdon tube is connected by a link 12 with a segmental rack 13 which ispivotally mounted in the casing and meshes with a pinion 14 of a pivotstaff 15also mounted in the easing. A disk 16 of insulating material issecured to the face of the casing in any suitable manner and forms apivotal support for the rack 13 and the pivotal staff 15, there being agage hand 17 in frontof the insulating disk mounted on the pivotal staff15 and insulated therefrom. At one end the sheet iron gage hand 17 hasan outwardly bent flange 18 forming the armature of a permanent magnet19 which is adj ustably mounted on the insulating disk by means of acleat 20. The gage hand 17 may however be separate from its armature andof any desirable material and the permanent ma net may be replaced. byan electromagnet if desired. Theother end of the gage hand 17 isconnected by means of a flexible conductor 21 with a binding post 22 onthe insulating disk and carries on a reduced extension a cylindricalcontact block 23, preferably of carbon, which is adapted to en gage asimilar contact block 24: carried on the end of a leaf spring 25. Thespring 25 is secured at 26 to the insulating disk at one end and has itsother end confined between the .walls of a notch in an outwardly bentflange 27 of a stop bracket 28, another outwardly bent flange 29 ofwhich forms an additional stop for engaging the spring.

Behind the insulating disk a blow-out magnet 30 has its core connectedto the easing at one end and to an elongated pole piece 31 at the otherend, which pole piece lies close to the insulating disk and just behindthe point of engagement between the contact blocks 23 and 24:. A similarpole piece 32 is formed by a lug on the cover 7 directly opposite thepole piece 31 and these pole pieces form the poles of the blowoutmagnet, the casing and its cover being they break the circuit betweenthem the arc will be disrupted by the blow-out magnet. The insulatingdisk forms a guard for the pole piece 31 and a plate of insulatingmaterial 33 is secured to the pole piece 32 to form a guard therefor.

A binding post ing is connected by a wire 35 with one end of the windingof the blow-out magnet and a wire 36 connects binding post 22 with theother end of said winding, there being another binding post 37 on theback of the casing which connects with the bracket 26 of the contactspring. The binding post 3a is adapted to be connected with a wire 38fromthe trolley or other source of electrical supply and the bindingpost 37 is adapted to be connected by a wire 39 with the motor 40 of acompressor 41, the other side of the motor being connected by a wire 2with the ground.

Tn operation the pressure within the reservoir 11 of the fluid pressuresystem causes the Bourdon tube 9 to change its position so as to movethe gage hand 17 clockwise or anti-clockwise as the pressure increasesor diminishes. As long as the pressure in the reservoir is below apredetermined maximum the rage hand will be in the position shown inFig. 1, with the armature 18 held against the permanent magnet and thecontacts 23 and 2 1 in engagement with each other, so that the circuitis complete from the trolley wire38, through the blow-out magnet coil30, by wires 36 and 21 to the insulated gage hand 17 and through theengaging contact blocks 23 and 24 and the spring 25 to the binding post37, and through the wire 39 motor 40 and wire 42 to the ground. Themotor is therefore caused to operate and drive the compressor andrestore pressure in the reservoir 11. As soon as the pressure in thereservoir 11 reaches a predetermined maximum, determined by the strengthand dosition of the permanent magnet 19, the tendency of the Bourdontube to move the gage hand away irom the'permanent magnet becomesgreater than the attraction of said magnet and consequently the gagehand is quickly moved away from the magnet with a quick separation ofcontact blocks 23 and 24 which breaks the circuit above traced anddeprives the motor of current, so that it remains idle until thepressure in the res- .crvoir has been reduced to a predeterminedminimum; As the-pressure in the reservoir is reduced by being drawn foruse in the air brake or other mechanism the gage hand is caused to swingback toward its original position, but as soon as the armature 18 comeswithin the field of influence of the permanent magnet 19 the gage handis quickly thrown by the attraction of the magnet into its closedposition, as shown in Fig. 1. The

presence of the permanent magnet thereby assures a quick make and breakof the motor circuit within a close range of pressure, which however maybe varied at will by changing the position of the permanent magnet or bysubstituting a magnet of different strength. The yielding contact block34- on the back of the casl 24 prevents a separation of the contactblocks when the tendency of the pressure in the Bourdon tube 'is aboutequal to the opposing tendency of the permanent magnet, at which timethe gage hand is liable to waver slightly. The yielding contact block 21 also assures a perfect engagement between the contacts notwithstandingwear thereof. The blow-out magnet prevents burning of the contact blocksby arcing at the time of their separation and the arc is directed awayfrom the other parts of the switch mechanism. The pole pieces 31 and 32are protected from the are by the insulating disk 16 and the insulatingplate 33 respectively.

The invention is not restricted to the use of any particular form ofpressure switch as a diaphragm or other construction may be substitutedfor the one shown.

By means of this invention the pressure actuated switch is adapted forcontrolling the motor circuit alone, without the necessity for auxiliaryor supplemental switches and is therefore less expensive and less liableto get out of order, while being more efiicient and having a narrowerrange of pressure than other switch structures for this purpose.

That I claim as my invention is;

l. A pressure governor for fluid pressure systems, comprising an ironcasing, a Bourdon tube mounted therein and having connection with thepressure system, a gage hand having operative connection with theBourdon tube whereby it is caused to move as the result of changes inpressure in the pressure system, an insulating disk in the casing, aswitch contact mounted on the age hand, a second switch contact mounteon the insulating disk and adapted to be engaged and disengaged by theswitch contact of the gage hand, a permanent magnet mounted on theinsulating disk, an armature therefor carried by the gage hand, saidmagnet tending to hold the gage hand in position to close the switchcontacts, a blow-out magnet having its core connected to the casing, apole piece on the blow-out magnet beneath the insulating disk andadjacent to the switch contacts, ing, a boss on the cover constitutingthe other pole piece for the blow-out magnet and also located adjacentto the switch contacts, and an insulating plate on the boss.

2. A pressure governor, comprisi'ngapressure gage having a gage handadapted to be moved by variations in ressure, switch contacts engagingand isengaging by the movements of the gage hand, a permanent horse-shoemagnet, and an armature for the magnet carried by the gage hand to closethe magnetic circuit between the two poles of the magnet, whereby themagnet is adapted to quickly move the ga e hand for engaging the switchcontacts when its armature is brought into its field of influence and isan iron cover for the casadapted to detain the gage hand until thepressure is suffic ent to overcome its influence and thereby effect aquick disengage- I magnetic circuit between the poles of the horse-shoemagnet, a blow-out magnet mounted Within the casing behlnd the in- 3. Apressure governor, comprising an switch contacts, and an iron cover forthe iron casing, an insulating plate extending casing having aprojecting lug positioned in over the front of the casing, a pressuregage front of the switch contacts to constitute the within the casingbehind the insulating plate other polepiece of the blow-out magnet. andprovided with a gage hand in front of In testimony whereof, I afiix mysignature, 10 the insulating platle, switch contacts in front inpresence of tWo Witnesses. v

of the insulatin ate ada )ted to be brou ht into and out o? Zangagernent by the moie- WALTER RICHARDS ments of the gage hand, a horse-shoemagnet Witnesses: secured to the insulating plate, an armature ANNA F.SOHMIDTBAUER, 15 carried by the gage hand for closing the S. G.CALDWELL.

ment of the switch contacts. sulating plate With a pole piece'behind the

